Where might this conversation be heard?

M Hello, I got this paper on my door. I guess I wasn’t home to receive a package.
W O.K. We can get it for you, but you’ll have to take a number and wait for your turn. There are numbers on the wall behind you.
M Oh, I didn’t see them. Where can I get an envelope to send this letter?
W They are by the front entrance. You can just put it in the envelope and pay for it when it’s your turn.